Internal emails reveal the nation’s top consumer cop fears political parties’ use of big data is ‘harmful’.

Australian Competition and Consumer Commission chairman Rod Sims’ concerns came to light after an unknown person used freedom of information laws to obtain and exchange between him and staff working on the ‘digital platforms’ inquiry.

Demands are now being made for an end to parties’ exemption from privacy and spamming laws, as well as the introduction of new rules covering psychological influencing on social media.